Abstract Chlamydia trachomatis (Ct) is the most commonly reported sexually transmitted infection in the U.S., is a major cause of infertility, pelvic inflammatory disease and ectopic pregnancy among women and has been associated with increased HIV acquisition. Because women experience the most severe sequelae, the focus of Ct prevention in the U.S. has been on screening sexually active women < 25 years old. Though men are reservoirs of the infection, the Centers for Disease Control and Prevention have not recommended targeting men due to lack of evidence for this approach. This research will fill this gap. African American (AA) women are 7.5 times more likely to be infected with Ct than whites, thus AA are the focus of this research. We hypothesize that screening AA men is essential to curbing the high rates of Ct among young AA women and that a bundled approach will by synergistic. Our community-based pilot program, called ?Check it,? is a pilot- tested male screening program which targeted AA men aged 15-25. At the core of this intervention is male Ct screening, but it is also bundled with other evidence-based and best practices for Ct control including: venue- based sampling (VBS), social network peer referral, modest monetary incentives (MMI), screening of target men, rescreening of target men found to be Ct positive with text reminders (Text-RS) , expedited treatment for index men (EIT) and for the partners (EPT), and Wed-based education (Web-Ed). The goal of this study is to examine the effectiveness of a pilot-tested, bundled Ct prevention program focusing on screening young AA men for the prevention of Ct among young AA women: Aim 1. To determine the impact of Check it on women's Ct rates ? This aim has a formative phase and an intervention phase. In the formative phase, the pilot Check it is developed and manualized. In the intervention, Check it is implemented and evaluated. We hypothesize that, post-intervention, Ct rates among AA women in the intervention community will be significantly lower compared to rates in the control communities, and that Check it will result in high rates of index/partner treatment and rescreening. Aim 2. To model the potential impact and optimal coverage needed - Using inputs from this study and the literature, a deterministic population-based epidemiological model will be used to model the number of cases averted by Check it and to determine the potential impact at different intensities of the intervention. Aim 3. To determine the cost effectiveness of Check it - Time motion studies will be conducted and used as inputs for the cost-benefit/effectiveness analysis of the Check it Program in order to distinguish study from program costs. If Check it is found to be effective as hypothesized, we will conduct future translational research to disseminate the program. This research has the potential for practical application by improving reproductive health and high impact by removing disparities in the control of Ct among AA men. .